JP3927373B2 - Hydraulic control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic control device for an automatic transmission, and more particularly to hydraulic control for discharging air mixed in a hydraulic circuit.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a hydraulic control device for an automatic transmission that controls the engagement / release of a friction engagement element with a hydraulic pressure, a friction engagement element (clutch or brake) to be released from the request of the gear stage at that time during non-shift On the other hand, a configuration is known in which air mixed in the hydraulic circuit is discharged by periodically supplying hydraulic pressure within a range in which the piston does not stroke (see Japanese Patent Laid-Open No. 10-169764).
[0003]
[Problems to be solved by the invention]
By the way, in the air discharge control described above, since the hydraulic pressure is supplied to the friction engagement element that should be released from the request for the gear position at that time, it is based on the shift request when the hydraulic pressure is supplied. When the engagement control is started, the engagement control is started from an initial pressure higher than usual, and the engagement is accelerated and a shift shock may be generated.
[0004]
Therefore, the air discharge control is preferably performed only when air is actually mixed in the hydraulic circuit. However, conventionally, the air discharge control is performed without determining whether or not air is actually mixed. Since the air is actually mixed, there is a problem that the hydraulic pressure supply for discharging the air is performed even if the air is not actually mixed, which may cause unnecessary adverse effects on the shift control. there were.
[0005]
The present invention has been made in view of the above problems, and determines whether or not air (bubbles) is mixed in the hydraulic circuit, and forcibly supplies hydraulic pressure only when air is actually mixed. An object of the present invention is to make it possible to avoid the influence on shifting as much as possible.
[0006]
[Means for Solving the Problems]
Therefore, according to the first aspect of the present invention, the hydraulic pressure is forcibly supplied to the friction engagement element to be released at the current gear stage during non-shifting, thereby automatically discharging air mixed in the hydraulic circuit. In the hydraulic control device for the transmission, when the temperature of the engine or the automatic transmission at the start of the engine combined with the automatic transmission is lower than a reference temperature, the forced hydraulic supply for discharging the air is performed. On the other hand, when the temperature is equal to or higher than the reference temperature, when the air discharge control is not performed during the previous operation, and when the air discharge control is not performed during the scheduled period although the air discharge control is performed. Is configured to perform forced oil pressure supply for air discharge.
[0009]
According to such a configuration, when the temperature of the engine or the automatic transmission at the time of starting is lower than the reference temperature, it is estimated that a predetermined time or more has elapsed since the previous operation and air is mixed in the hydraulic circuit during that time. Thus, hydraulic pressure is supplied to the frictional engagement element that should be released. Also, if the temperature at the start is high and the air discharge control has not been completed during the previous operation, even if air is not mixed during the previous stop period, Since mixed air may remain without being discharged, hydraulic pressure supply for air discharge is forced.
[0010]
In a second aspect of the invention, the engine coolant temperature is determined as a parameter representative of the engine temperature. According to a third aspect of the present invention, the temperature of the hydraulic oil for the automatic transmission is determined as a parameter representing the temperature of the automatic transmission. In the invention of claim 4, wherein the reference temperature, and configured to change low as when the outside air temperature is low.
[0011]
According to such a configuration, when the outside air temperature is low, the temperature of the engine or the automatic transmission decreases rapidly with the passage of time, so the reference temperature is set lower as the outside air temperature is lower. According to the fifth aspect of the present invention, the automatic transmission for discharging the air mixed in the hydraulic circuit by forcibly supplying the hydraulic pressure to the friction engagement element to be released at the current shift stage during non-shifting. In the hydraulic control device of the machine, when the stop time of the engine combined with the automatic transmission exceeds a reference time, the forced hydraulic pressure supply for discharging the air is performed, while the stop time is equal to or less than the reference time. When the air discharge control is not performed at the time of the previous operation, and when the air discharge control is not performed only for the scheduled period although the air discharge control is performed, the forced discharge for the air discharge is performed. The system is configured to perform a general hydraulic supply.
[0012]
According to such a configuration, when the stop time of the engine exceeds the reference time, and estimated that the air in the hydraulic circuit is mixed during, Ru to perform the hydraulic supply to the friction engagement element to be released originally. On the other hand, even if the engine is stopped and restarted within a short period of time, if air discharge control has not been completed during the previous operation, air is mixed in during the previous stop period. If not, the air mixed before that may remain without being discharged, so the hydraulic pressure supply for air discharge is forced.
[0014]
【The invention's effect】
According to the first to third aspects of the present invention, it is possible to easily determine the period during which the hydraulic pressure supply to the hydraulic circuit is stopped based on the temperature at the time of restart, and it is easy to supply the hydraulic pressure only when air is actually mixed. It is possible to prevent the air discharge control from being canceled because the stop period is short even though the air remains without being completely discharged, and the air can be discharged reliably. There is an effect.
[0015]
According to the invention of claim 4, even if the outside air temperature is different, there is an effect that it is possible to accurately determine the period during which the hydraulic pressure supply to the hydraulic circuit is stopped from the temperature at the time of restart.
[0016]
According to the invention described in claim 5, it can be determined accurately time the hydraulic supply has been stopped for the hydraulic circuit by the stop of the engine, actually whether air in the hydraulic circuit is mixed with higher accuracy can be determined In the state where the air remains without being completely discharged, it is possible to avoid that the air discharge control is canceled because the stop period is short, and the air can be discharged reliably. .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 shows a drive system of a vehicle in an embodiment. An automatic transmission 3 is connected to an output shaft of an engine 1 via a torque converter 2, and is illustrated by an output shaft of the automatic transmission 3. The drive wheels of the vehicle that do not rotate are driven to rotate.
[0018]
FIG. 2 is a skeleton showing the speed change mechanism portion of the automatic transmission 3.
The transmission mechanism section includes two sets of planetary gears G1, G2, three sets of multi-plate clutches (high clutch H / C, reverse clutch R / C, low clutch L / C), one set of brake bands 2 & 4 / B, One set of multi-plate brakes (low & reverse brake L & R / B) and one set of one-way clutch L / OWC.
[0019]
The two sets of planetary gears G1 and G2 are simple planetary gears composed of sun gears S1 and S2, ring gears r1 and r2, and carriers c1 and c2, respectively.
The sun gear S1 of the planetary gear set G1 is configured to be connectable to the input shaft IN by a reverse clutch R / C, and is configured to be fixed by a brake band 2 & 4 / B.
[0020]
The sun gear S2 of the planetary gear set G2 is directly connected to the input shaft IN.
The carrier c1 of the planetary gear set G1 is configured to be connectable to the input shaft IN by a high clutch H / C, while the ring gear r2 of the planetary gear set G2 is a carrier of the planetary gear set G1 by a low clutch L / C. The carrier c1 of the planetary gear set G1 can be fixed by a low & reverse brake L & R / B.
[0021]
A ring gear r1 of the planetary gear set G1 and a carrier c2 of the planetary gear set G2 are directly and integrally connected to the output shaft OUT.
In FIG. 2, reference numeral 21 denotes an oil pump (hydraulic pump) that is driven by the engine 1 and supplies hydraulic oil to the automatic transmission.
In the speed change mechanism having the above-described configuration, forward 1st to 4th speeds and reverse R are realized by a combination of engagement / release states of the respective clutches and brakes (friction engagement elements) as shown in FIG.
[0022]
In FIG. 3, the circles indicate the engaged state, and the parts not marked with the symbol indicate that they are in the released state. In particular, the engaged state indicated by the black circle of the low & reverse brake L & R / B at the first speed. Indicates fastening in only one range.
The above engagement / release logic of the friction engagement element is realized by a combination of ON / OFF of the shift solenoid (A) 5 and the shift solenoid (B) 6 inserted in the control valve 4 for shift control shown in FIG. (See FIG. 4).
[0023]
A line pressure solenoid 7 is inserted into the control valve 4, and the line pressure of the control valve 4 is controlled by the line pressure solenoid 7.
The shift solenoid (A) 5, the shift solenoid (B) 6 and the line pressure solenoid 7 are controlled by an A / T controller 11.
The A / T controller 11 includes an ATF temperature sensor 12 that detects the temperature of an ATF (automatic transmission fluid (hereinafter referred to as ATF)), and a throttle valve that throttles the intake of the engine 1 in conjunction with an accelerator pedal (not shown). 8, a throttle opening sensor 13 for detecting an opening degree TVO, a vehicle speed sensor 14 for a vehicle traveling speed VSP, an engine rotation sensor 15 for detecting a rotational speed Ne of the engine 1, and a range position selected by operating a shift knob. Detection signals are input from the inhibitor switch 16, the water temperature sensor 17 for detecting the coolant temperature of the engine 1, the outside temperature sensor 18 for detecting the outside air temperature, the oil temperature sensor 19 for detecting the temperature of the lubricating oil of the engine 1, and the like. The ON / OFF signal from the ignition switch 20 It is a force.
[0024]
The A / T controller 11 performs normal shift control based on the above various detection signals, while executing the control program shown in the flowchart of FIG. Control is performed to discharge air (bubbles) mixed in the circuit.
In the flowchart of FIG. 5, in step S1, it is determined whether or not the ignition switch 20 is switched from OFF to ON. If the ignition switch 20 is switched to ON, the process proceeds to step S2.
[0025]
In step S2, the detection signal from the outside air temperature sensor 18 is read to detect the outside air temperature.
In step S3, a reference temperature TMP is set according to the outside air temperature detected in step S2. The reference temperature TMP is set to a higher temperature as the outside air temperature is higher.
[0026]
In step S4, the detection signal from the water temperature sensor 17 is read to detect the cooling water temperature.
The cooling water temperature is a parameter representative of the temperature of the engine 1. Instead of the cooling water temperature, the temperature of the lubricating oil may be detected based on a detection signal from the oil temperature sensor 19. Instead of the temperature of 1, the temperature of the ATF representing the temperature of the automatic transmission 3 may be detected based on the detection signal from the ATF temperature sensor 12.
[0027]
In step S5, the coolant temperature (or lubricating oil temperature or ATF temperature) detected in step S4 is compared with the reference temperature TMP set in step S3.
When the cooling water temperature (or lubricating oil temperature or ATF temperature) detected in step S4 is lower than the reference temperature TMP, the process proceeds to step S7, and it is estimated that air is mixed in the hydraulic circuit.
[0028]
The state where the cooling water temperature (or the lubricating oil temperature or the ATF temperature) is lower than the reference temperature TMP indicates that a predetermined time or more has passed since the engine 1 was stopped, and the hydraulic circuit is supplied to the hydraulic circuit for the predetermined time or more. By leaving the hydraulic pressure supply in a stopped state, it is predicted that air will be mixed into the hydraulic circuit.
On the other hand, when the cooling water temperature (or lubricating oil temperature or ATF temperature) detected in step S4 is equal to or higher than the reference temperature TMP, the process proceeds to step S6.
[0029]
In step S6, it is determined whether or not the air discharge control is performed during the previous operation and the air discharge control is performed only during a scheduled period.
If it is determined in step S6 that the air discharge control has not been performed during the previous operation or the air discharge control has been performed but it has been determined that the engine 1 has been stopped without being completed to the end, the step S7 It is estimated that the air is mixed in the hydraulic circuit.
[0030]
In addition, when air discharge control is performed during the previous operation, and air discharge control is performed only for a scheduled period and the air discharge is completed, the process proceeds to step S8 and air is mixed into the hydraulic circuit. It is estimated that it is not in the state.
If the cooling water temperature (or lubricating oil temperature or ATF temperature) detected in step S4 is equal to or higher than the reference temperature TMP, the engine 1 is restarted before the temperature is greatly reduced after being stopped. It is estimated that there is no air mixing in the period since the period during which was stopped was short.
[0031]
However, if the air discharge control is not completed during the previous operation, the air mixed before that may remain without being discharged, so the period during which the engine 1 has been stopped is short. If the air discharge control is not completed during the previous operation, the air mixing state is estimated.
When it is determined in step S8 that air is not mixed, this program is terminated without performing hydraulic pressure supply control for discharging air.
[0032]
Therefore, air discharge control is performed in a state where air is not actually mixed, and adverse effects on normal shift control are avoided.
On the other hand, when it is determined in step S7 that there is a possibility that air is mixed, hydraulic control for discharging air is performed in step S9 and subsequent steps.
In step S9, it is determined whether or not an air discharge control execution permission condition is satisfied.
[0033]
As the execution permission condition, for example, the following conditions (1) to (3) are determined.
(1) The D range (drive range) state that is first switched from the N range (neutral range) after the ignition switch is turned on.
(2) The line pressure control (ND select control) performed in a predetermined time immediately after switching from the N range to the D range is completed.
[0034]
(3) The first speed steady state where there is no shift request.
When the execution permission condition is satisfied, the process proceeds to step S10, and air discharge control for forcibly supplying hydraulic pressure to the friction engagement element to be released at the gear position (first speed) at that time is executed.
Specifically, both the shift solenoid (A) 5 and the shift solenoid (B) 6 are periodically switched OFF.
[0035]
In the first speed, both the shift solenoid (A) 5 and the shift solenoid (B) 6 are controlled to be in the ON state, the high clutch H / C is released, and the low clutch L / C is engaged. The state where both the shift solenoid (A) 5 and the shift solenoid (B) 6 are OFF corresponds to the state of the third speed, and at the third speed, the low clutch L / C and the high clutch H / C are engaged (FIGS. 3 and 4). reference).
[0036]
Accordingly, by periodically switching both the shift solenoid (A) 5 and the shift solenoid (B) 6 OFF, the hydraulic pressure is periodically supplied to the high clutch H / C to be released at the first speed. As a result, air mixed in the hydraulic circuit of the high clutch H / C is discharged by supplying the hydraulic pressure.
In step S11, it is determined whether or not the execution time of the air discharge control has reached a predetermined time, and the process returns to step S9 until the predetermined time is reached. The completion of the discharge control is determined and the program is terminated.
[0037]
Note that the step S6 may be omitted, and only the entry of air into the hydraulic circuit while the engine 1 is stopped may be determined based on whether or not the temperature has decreased to the reference temperature.
FIG. 6 is a flowchart showing a second embodiment of air discharge control.
In step S21, it is determined whether the ignition switch 20 is ON or OFF.
[0038]
When the ignition switch 20 is OFF, the process proceeds to step S22, and it is determined whether or not it is the first time when the ignition switch 20 is switched from ON to OFF.
If it is the first time, the process proceeds to step S23 and the value of the timer timer is reset to zero.
If it is not the first time, the process proceeds to step S24, where the result obtained by adding 1 to the previous value of the timer timer is set as the current value, and the value of the timer timer is counted up every execution period of the program executed every predetermined time. .
[0039]
As a result, the timer timer measures the elapsed time from when the ignition switch 20 is turned off.
If it is determined in step S21 that the ignition switch 20 is ON, the process proceeds to step S25, and the value of the timer timer is compared with the reference time TIM.
[0040]
Since the timer timer measures the elapsed time from when the ignition switch 20 is turned off, in step S25, the time when the ignition switch 20 is turned off is determined.
When it is determined in step S25 that the value of the timer timer exceeds the reference time TIM, the process proceeds to step S27, and it is estimated that air is mixed in the hydraulic circuit.
[0041]
When it is determined that the value of the timer timer exceeds the reference time TIM, the time during which the engine 1 has been stopped, in other words, the time during which the hydraulic pressure supply to the hydraulic circuit is stopped is longer than a predetermined time. It is estimated that air is mixed in the hydraulic circuit during that time. On the other hand, when it is determined in step S25 that the value of the timer timer is equal to or less than the reference time TIM, the process proceeds to step S26.
[0042]
In step S26, it is determined whether or not the air discharge control is performed during the previous operation and the air discharge control is performed only during a scheduled period.
When it is determined that the value of the timer timer is equal to or less than the reference time TIM, the time during which the engine 1 is stopped, in other words, the time when the hydraulic pressure supply to the hydraulic circuit is stopped is short, However, if the air discharge control is not completed during the previous operation, there is a possibility that there is air remaining without being discharged, and the process proceeds to step S27. .
[0043]
On the other hand, when it is determined in step S26 that the air discharge control has been completed during the previous operation, it is determined that there is no mixed air during the stop and there is no air remaining without being discharged. The process proceeds to step S28, where it is determined that air is not mixed, and the program is terminated.
If it is determined in step S27 that air is mixed in the hydraulic circuit, it is determined in step S29 whether or not an air discharge control execution permission condition is satisfied, as in step S9.
[0044]
When the execution permission condition is satisfied, the process proceeds to step S30, and as with step S10, the hydraulic pressure is forcibly applied to the friction engagement element (high clutch H / C) to be released at the gear position (first gear) at that time. Air discharge control to supply
In step S31, it is determined whether or not the execution time of the air discharge control has reached a predetermined time, and the process returns to step S29 until the predetermined time is reached. The completion of the discharge control is determined and the program is terminated.
[0045]
Note that the determination in step S26 may also be omitted in the second embodiment.
[Brief description of the drawings]
FIG. 1 is a system diagram showing a vehicle drive system in an embodiment.
FIG. 2 is a skeleton diagram showing a speed change mechanism in the embodiment.
FIG. 3 is a diagram showing a combination of engagement states of frictional engagement elements at gear positions in the embodiment.
FIG. 4 is a diagram showing a combination of ON / OFF of shift solenoids A and B at each gear position in the embodiment.
FIG. 5 is a flowchart showing a first embodiment of air discharge control.
FIG. 6 is a flowchart showing a second embodiment of air discharge control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Torque converter 3 ... Automatic transmission 4 ... Control valve 5 ... Shift solenoid (A)
6. Shift solenoid (B)
7 ... Line pressure solenoid 11 ... A / T controller 12 ... ATF temperature sensor 13 ... Throttle opening sensor 14 ... Vehicle speed sensor 15 ... Engine rotation sensor 16 ... Inhibitor switch 17 ... Water temperature sensor 18 ... Outside air temperature sensor 19 ... Oil temperature sensor 20 ... Ignition switch 21 ... Oil pump G1, G2 ... Planetary gear H / C ... High clutch R / C ... Reverse clutch L / C ... Low clutch 2 & 4 / B ... Brake band L & R / B ... Low & reverse brake L / OWC ... One way clutch

Claims (5)

In a hydraulic control device for an automatic transmission that discharges air mixed in a hydraulic circuit by forcibly supplying hydraulic pressure to a friction engagement element to be released at the current shift stage during non-shifting,
While the temperature of the engine or the automatic transmission at the time of starting the engine in combination with the automatic transmission, when below the reference temperature, to perform a forced supply of hydraulic pressure for the air discharge,
When the temperature is equal to or higher than the reference temperature, when the air discharge control is not performed at the time of the previous operation, and when the air discharge control is not performed only during the scheduled period of the air discharge control, A hydraulic control device for an automatic transmission, which is configured to perform forced hydraulic supply for discharging the air . As a parameter representative of the temperature of the engine, the hydraulic control device for the automatic transmission according to claim 1, characterized in that to determine the coolant temperature of the engine. Wherein the automatic transmission parameter representative of the temperature of the hydraulic control device for an automatic transmission according to claim 1, characterized in that to determine the temperature of the hydraulic fluid of the automatic transmission. Wherein the reference temperature, the hydraulic control device for an automatic transmission according to any one of claims 1 to 3, characterized in that to change as the lower time outside air temperature is low. In a hydraulic control device for an automatic transmission that discharges air mixed in a hydraulic circuit by forcibly supplying hydraulic pressure to a friction engagement element to be released at the current shift stage during non-shifting,
When the stop time of the engine in combination with the automatic transmission exceeds the reference time, while causing the forced supply of hydraulic pressure for the air discharge,
When the stop time is equal to or shorter than the reference time, when air discharge control is not performed at the time of the previous operation, and when air discharge control is not performed only for a scheduled period although air discharge control is performed. A hydraulic control device for an automatic transmission, which is configured to perform forced hydraulic supply for discharging the air .

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